scholarly journals Changing characteristics of atmospheric CH<sub>4</sub> on the Tibetan Plateau, records from 1994 to 2017 at Mount Waliguan station

2020 ◽  
Author(s):  
Shuo Liu ◽  
Shuangxi Fang ◽  
Peng Liu ◽  
Miao Liang ◽  
Minrui Guo ◽  
...  
Keyword(s):  
Growth Rate ◽  
Tibetan Plateau ◽  
Global Climate ◽  
Source Area ◽  
Annual Growth ◽  
The Tibetan Plateau ◽  
Annual Growth Rate ◽  
Northern India ◽  
City Regions ◽  
Long Term Observation

Abstract. A 24-year long-term observation of atmospheric CH4 was presented at Mt. Waliguan (WLG) station, the only WMO/GAW global station in inland of Eurasia. Overall, during 1994–2017, continuously increase of atmospheric CH4 was observed at WLG with yearly growth rate of 5.1 ± 0.1 ppb yr−1, although near-zero and even negative growth appeared in some particular periods, e.g., 1999–2000, and 2004–2006. The average CH4 mole fraction was only 1805.8 ± 0.1 ppb in 1995, but unprecedented elevated ~ 100 ppb and reached a historic high of 1903.8 ± 0.1 ppb in 2016. The seasonal averages of atmospheric CH4 at WLG were ordered by summer, winter, autumn and spring, and the correlation slopes of ΔCO/ΔCH4 showed a maximum in summer and minimum in winter, which was almost opposite to other sites in the northern hemisphere, e.g., Mauna Loa, Jungfraujoch, and was caused by regional transport. Strong potential sources at WLG were predominately identified in northeast (cities, e.g., Xining, Lanzhou) and southwest (the Northern India), and air masses from west and northwest regions were accompanied with higher CH4 mole fractions than that from city regions. What is interesting is that obviously changes appeared in different observing periods. Generally, (i) the amplitudes of diurnal or seasonal cycles were continuously increasing over time, (ii) the wind sectors with elevated CH4 moved from ENE- ... -SSE sectors in early periods to NNE- ... -E sectors (city regions) in later years, (iii) the area of source regions was increasing along with the years, and strong sources gradually shifted from northeast to southwest, (iv) the annual growth rates in recent years (e.g., 2013–2016) were significantly larger than that in early periods (e.g., 1998–2012). We conclude that the site was more and more affected by regional sources along with the time. Northern India was possibly becoming the strongest source area to WLG rather than city regions before. The case study in the Tibetan Plateau showed that the atmospheric CH4 observed in Qinghai-Tibetan Plateau changed not as expected, the annual growth rate was even larger than that in city regions in some period (e.g., 7.3 ± 0.1 ppb yr−1 in 2013–2016). It is unambiguous that the anomalously fluctuations of atmospheric CH4 in this region are a warning to the world, its increasingly annual growth rate may be a dangerous signal to global climate change.

scholarly journals Measurement report: Changing characteristics of atmospheric CH<sub>4</sub> in the Tibetan Plateau: records from 1994 to 2019 at the Mount Waliguan station

2021 ◽  
Vol 21 (1) ◽  
pp. 393-413
Author(s):  
Shuo Liu ◽  
Shuangxi Fang ◽  
Peng Liu ◽  
Miao Liang ◽  
Minrui Guo ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Atmospheric Methane ◽  
Continuous Increase ◽  
Northern India ◽  
Source Regions ◽  
City Regions

Abstract. A 26-year, long-term record of atmospheric methane (CH4) measured in situ at the Mount Waliguan (WLG) station, the only World Meteorological Organization (WMO) and Global Atmosphere Watch (GAW) global station in inland Eurasia, is presented. Overall, a nearly continuous increase in atmospheric CH4 was observed at WLG, with a yearly growth rate of 5.1±0.1 parts per billion (ppb) per year during 1994–2019, except for some particular periods with near-zero or negative values, e.g., 1999–2000 and 2004–2006. The average CH4 mole fraction was only 1799.0±0.4 ppb in 1994 but increased to about 133 ppb and reached a historic level of 1932.0±0.1 ppb in 2019. The case study in the Tibetan Plateau showed that the atmospheric CH4 increased rapidly. During some special periods, it is even larger than that of city regions (e.g., 6.7±0.2 ppb yr−1 in 2003–2007). Generally, the characteristics of CH4 varied in different observing periods as follows: (i) the diurnal cycle has become apparent and the amplitudes of the diurnal or seasonal cycles increased over time; (ii) the wind sectors with elevated CH4 mole fractions switched from ENE-E-ESE-SE-SSE sectors (wind directions) in early periods to NNE-NE-ENE-E sectors in later years; (iii) the area of source regions increased as the years progressed, and strong sources shifted from northeast (city regions) to southwest (northern India); and (iv) the annual growth rates in recent years (e.g., 2008–2019) were significantly larger than those in the early periods (e.g., 1994–2007).

Ageing Saudi Population in the Facebook Era

2018 ◽  
Author(s):  
Asharaf Abdul Salam
Keyword(s):  
Growth Rate ◽  
Saudi Arabia ◽  
Population Ageing ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Saudi Population ◽  
Aged Population ◽  
Facebook Usage

<p>Data pertaining to 1974, 1992, 2004 and 2010 Censuses in Saudi Arabia was collected. Some reviews and literature on population ageing in Saudi Arabia as well as Facebook usage obtained. Statistics pertaining to Saudi population was utilized.</p> <p>Aged population in 2010 estimated by assuming the annual growth rate of 1974-2004.</p>

scholarly journals Association between triglyceride-glucose index and risk of arterial stiffness: a cohort study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Shouling Wu ◽  
Luli Xu ◽  
Mingyang Wu ◽  
Shuohua Chen ◽  
Youjie Wang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Linear Regression ◽  
Arterial Stiffness ◽  
Multivariate Linear Regression ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Cross Sectional ◽  
Tyg Index ◽  
Longitudinal Association ◽  
The Cross

Abstract Background Triglyceride–glucose (TyG) index, a simple surrogate marker of insulin resistance, has been reported to be associated with arterial stiffness. However, previous studies were limited by the cross-sectional design. The purpose of this study was to explore the longitudinal association between TyG index and progression of arterial stiffness. Methods A total of 6028 participants were derived from the Kailuan study. TyG index was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Arterial stiffness was measured using brachial-ankle pulse wave velocity (baPWV). Arterial stiffness progression was assessed by the annual growth rate of repeatedly measured baPWV. Multivariate linear regression models were used to estimate the cross-sectional association of TyG index with baPWV, and Cox proportional hazard models were used to investigate the longitudinal association between TyG index and the risk of arterial stiffness. Results Multivariate linear regression analyses showed that each one unit increase in the TyG index was associated with a 39 cm/s increment (95%CI, 29–48 cm/s, P < 0.001) in baseline baPWV and a 0.29 percent/year increment (95%CI, 0.17–0.42 percent/year, P < 0.001) in the annual growth rate of baPWV. During 26,839 person-years of follow-up, there were 883 incident cases with arterial stiffness. Participants in the highest quartile of TyG index had a 58% higher risk of arterial stiffness (HR, 1.58; 95%CI, 1.25–2.01, P < 0.001), as compared with those in the lowest quartile of TyG index. Additionally, restricted cubic spline analysis showed a significant dose–response relationship between TyG index and the risk of arterial stiffness (P non-linearity = 0.005). Conclusion Participants with a higher TyG index were more likely to have a higher risk of arterial stiffness. Subjects with a higher TyG index should be aware of the following risk of arterial stiffness progression, so as to establish lifestyle changes at an early stage.

scholarly journals Contrasting Evolution Patterns of Endorheic and Exorheic Lakes on the Central Tibetan Plateau and Climate Cause Analysis during 1988–2017

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1962
Author(s):  
Zhilong Zhao ◽  
Yue Zhang ◽  
Zengzeng Hu ◽  
Xuanhua Nie
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Climatic Factors ◽  
Global Climate ◽  
Rapid Expansion ◽  
Annual Precipitation ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Climate Change Research ◽  
Mean Temperature

The alpine lakes on the Tibetan Plateau (TP) are indicators of climate change. The assessment of lake dynamics on the TP is an important component of global climate change research. With a focus on lakes in the 33° N zone of the central TP, this study investigates the temporal evolution patterns of the lake areas of different types of lakes, i.e., non-glacier-fed endorheic lakes and non-glacier-fed exorheic lakes, during 1988–2017, and examines their relationship with changes in climatic factors. From 1988 to 2017, two endorheic lakes (Lake Yagenco and Lake Zhamcomaqiong) in the study area expanded significantly, i.e., by more than 50%. Over the same period, two exorheic lakes within the study area also exhibited spatio-temporal variability: Lake Gaeencuonama increased by 5.48%, and the change in Lake Zhamuco was not significant. The 2000s was a period of rapid expansion of both the closed lakes (endorheic lakes) and open lakes (exorheic lakes) in the study area. However, the endorheic lakes maintained the increase in lake area after the period of rapid expansion, while the exorheic lakes decreased after significant expansion. During 1988–2017, the annual mean temperature significantly increased at a rate of 0.04 °C/a, while the annual precipitation slightly increased at a rate of 2.23 mm/a. Furthermore, the annual precipitation significantly increased at a rate of 14.28 mm/a during 1995–2008. The results of this study demonstrate that the change in precipitation was responsible for the observed changes in the lake areas of the two exorheic lakes within the study area, while the changes in the lake areas of the two endorheic lakes were more sensitive to the annual mean temperature between 1988 and 2017. Given the importance of lakes to the TP, these are not trivial issues, and we now need accelerated research based on long-term and continuous remote sensing data.

scholarly journals Atmospheric Thermal and Dynamic Vertical Structures of Summer Hourly Precipitation in Jiulong of the Tibetan Plateau

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 505
Author(s):  
Yonglan Tang ◽  
Guirong Xu ◽  
Rong Wan ◽  
Xiaofang Wang ◽  
Junchao Wang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Tibetan Plateau ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
The Tibetan Plateau ◽  
Hourly Precipitation ◽  
Air Convection ◽  
Precipitation Variation ◽  
Long Term Observation

It is an important to study atmospheric thermal and dynamic vertical structures over the Tibetan Plateau (TP) and their impact on precipitation by using long-term observation at representative stations. This study exhibits the observational facts of summer precipitation variation on subdiurnal scale and its atmospheric thermal and dynamic vertical structures over the TP with hourly precipitation and intensive soundings in Jiulong during 2013–2020. It is found that precipitation amount and frequency are low in the daytime and high in the nighttime, and hourly precipitation greater than 1 mm mostly occurs at nighttime. Weak precipitation during the daytime may be caused by air advection, and strong precipitation at nighttime may be closely related with air convection. Both humidity and wind speed profiles show obvious fluctuation when precipitation occurs, and the greater the precipitation intensity, the larger the fluctuation. Moreover, the fluctuation of wind speed is small in the morning, large at noon and largest at night, presenting a similar diurnal cycle to that of convective activity over the TP, which is conductive to nighttime precipitation. Additionally, the inverse layer is accompanied by the inverse humidity layer, and wind speed presents multi-peaks distribution in its vertical structure. Both of these are closely related with the underlying surface and topography of Jiulong. More studies on physical mechanism and numerical simulation are necessary for better understanding the atmospheric phenomenon over the TP.

Abstract TP80: Incidence And Risk Factors For The Growth And Rupture Of Unruptured Cerebral Aneurysms. Results Of Annual Radiologic Follow Up Study.

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Katsumi Matsumoto ◽  
Kouichirou Tsuruzono ◽  
Manabu Sasaki ◽  
Noriyasu Yoshimura ◽  
Toshiki Yoshimine ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
Rupture Rate ◽  
Follow Up Study ◽  
Factors Influencing ◽  
Unruptured Cerebral Aneurysms

Background: The recent trend of the treatment of unruptured cerebral aneurysms(UIAs) is going to be conservative. Their natural history of rupture and growth is still unkown. We present the results of annual radiological follow-up study in UIAs. Method: In recent 12 years, we have found 121patients with 148 unruptured cerebral aneurysms were followed annually using 3D-CTA or MRA. Mean follow-up period was 5.5 year. Several factors influencing rupture or growth were statistically examined. Results: Among 121 patients, 9 ruptured and 11 showed growth of UIAs. Annual rupture rate was 1.3% per year and annual growth rate was 1.6% per year. Aneurysm size was the sole factor influencing rupture(P<0.001), whereas female sex and multiplicity were major factors influencing aneurysm growth(P<0.05). Under size 3mm, annual growth rate was 3.0% whereas annual rupture rate was 0.7%. In 4-6mm, growth rate was 1.6% and rupture rate was 1.6%. In 7-9mm, growth rate was 0 and rupture rate was 5.8%. In over 10mm, growth rate was 2.9% and rupture rate was 11.6%. Within 1 year, rupture occurred in 4 cases, and growth was found in 1 case. Conclusions: By annual radiological examination, growth of UIAs was noted more frequently than aneurysm rupture. Especially UIAs under 3mm, growth was 4 times higher than rupture, radiological follow up is effective for aneurysm rupture. Within 1 year, initially found UIAs should be carefully followed in a short interval.

The Impact of COVID-19 on Energy Consumption in the United States: An Overview

2021 ◽  
Author(s):  
Lindsey Kahn ◽  
Hamidreza Najafi
Keyword(s):  
Growth Rate ◽  
Energy Consumption ◽  
Energy Use ◽  
The United States ◽  
Average Annual Growth Rate ◽  
Annual Growth ◽  
Annual Growth Rate ◽  
End User ◽  
End Use ◽  
The Impact

Abstract Lockdown measures and mobility restrictions implemented to combat the spread of the novel COVID-19 virus have impacted energy consumption patterns, particularly in the United States. A review of available data and literature on the impact of the pandemic on energy consumption is performed to understand the current knowledge on this topic. The overall decline of energy use during lockdown restrictions can best be identified through the analysis of energy consumption by source and end-user breakdown. Using monthly energy consumption data, the total 9-months use between January and September for the years 2015–2020 are calculated for each end-use. The cumulative consumption within these 9 months of the petroleum, natural gas, biomass, and electricity energy by the various end-use sectors are compared to identify a shift in use throughout time with the calculation of the percent change from 2019 to 2020. The analysis shows that the transportation sector experienced the most dramatic decline, having a subsequent impact on the primary energy it uses. A steep decline in the use of petroleum and natural gas by the transportation sector has had an inevitable impact on the emission of carbon dioxide and other air pollutants during the pandemic. Additionally, the most current data for the consumption of electricity by each state and each end-user in the times before and during the pandemic highlights the impact of specific lockdown procedures on energy use. The average total consumption for each state was found for the years 2015–2019. This result is used calculation of yearly growth rate and average annual growth rate in 2020 for each state and end-user. The total average annual growth rate for 2020 was used to find a correlation coefficient between COVID-19 case and death rates as well as population density and lockdown duration. To further examine the relationship a correlation coefficient was calculated between the 2020 average annual growth rate for all sectors and average annual growth rate for each individual end-user.

Paleoaltitudinal histories for the northern and southern margins of the Tibetan Plateau during the Late Cenozoic: revealed by GDGTs

2021 ◽  
Author(s):  
Chihao Chen ◽  
Yan Bai ◽  
Xiaomin Fang ◽  
Haichao Guo ◽  
Weilin Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Miocene ◽  
Global Climate ◽  
The Tibetan Plateau ◽  
Lake Surface ◽  
Terrestrial Organic Matter ◽  
Plant Fossils ◽  
History Of ◽  
Monsoon System ◽  
Uplift History

&lt;p&gt;As an important driver of global climate change during the Cenozoic, the uplift of the Tibetan Plateau (TP) has strongly influenced the origination and evolution of the Asian monsoon system, and therefore the aridification of central Asia. Over the last two decades, the application of stable isotope paleoaltimeters and the discoveries of mammal and plant fossils have greatly promoted the understanding of the uplift history of the TP. However, paleoaltitudinal reconstructions based on different paleoaltimeters have suggested differing outcomes and therefore remain controversial. Novel paleoaltimeters have therefore needed to be developed and applied to constrain the uplift history of the TP more accurately and effectively by comparing and verifying multi-proxies. Paleothermometers based on glyceryl dialkyl glycerol tetraethers (GDGTs) are widely used in terrestrial and ocean temperature reconstructions. In this study, GDGT-based paleothermometers were tentatively applied to the Gyirong Basin on the southern TP, and the Xining Basins on the northern TP, in an attempt to quantitatively reconstruct their paleoaltitudes.&lt;/p&gt;&lt;p&gt;Both soil and aquatic-typed branched GDGTs have been identified from Late Miocene to Mid-Pliocene (7.0-3.2 Ma) samples taken from the Gyirong Basin; their reconstructed paleotemperatures were 7.5&amp;#177;3.3&amp;#176;C and 14.2&amp;#177;4.5&amp;#176;C, respectively. The former temperature may represent the mean temperature of the terrestrial organic matter input area, while the latter may represent the lake surface temperature. The results would suggest that the lake surface of the Gyirong Basin during the Late Miocene to Mid-Pliocene was 2.5&amp;#177;0.8 km and that the surrounding mountains exceeded 3.6&amp;#177;0.6 km, implying that the central Himalayas underwent a rapid uplift of ~1.5 km after the Mid-Pliocene.&lt;/p&gt;&lt;p&gt;GDGT-based paleotemperature reconstructions using MBT'&lt;sub&gt;5ME&lt;/sub&gt; values show that the Xining Basin dropped in temperature by ~10&amp;#176;C during the ~10.5-8 Ma period, exceeding that in sea surface temperatures and low-altitude terrestrial temperatures during these periods. By combining these results with contemporaneous tectonic and sedimentary records, we infer that these cooling events signaled the regional uplift with the amplitude of ~1 km of the Xining basins. Our results support that the TP was still growing and uplifting substantially since the Late Miocene, which may provide new evidence for understanding the growth, expansion and uplift patterns of the TP.&lt;/p&gt;

Authorship Pattern and Collaboration Coefficient of Library Professional’s Competency on Research Publications During 1999-2018: A Scientometric Analysis

2019 ◽  
Vol 9 (1) ◽  
pp. 85-89
Author(s):  
Nutan Gaud ◽  
M. P. Singh ◽  
Bhoopendra Singh
Keyword(s):  
Growth Rate ◽  
Doubling Time ◽  
The United States ◽  
Annual Growth ◽  
Scientometric Analysis ◽  
Annual Growth Rate ◽  
Authorship Pattern ◽  
Relative Growth ◽  
Compound Annual Growth Rate ◽  
Scopus Database

The present study aims to analysis authorship pattern and collaboration coefficient of library professional’s competency publications research from 1999-2018. The data has been downloaded by Scopus database. A total number of published articles during the period of study was 433 in the particular database on the topic of ‘professional’s competency’. The study examine various scientometric parameter such as authorship pattern, year wise distribution of publication, determine the annual growth rate and compound annual growth rate of publication, relative growth rate and doubling time of publication and so many. After the analysis, it is found that the highest 11.78% of an article published in the year 2015. The highest growth rate in 2000 and the lowest in 1999. The United States published highest 174 article and secured first place in top five countries wish distribution of the publication. Majority of the article is published by single authors is 171 articles during the period of study.

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